San Diego  Passengers and traffic at Lindbergh Field’s Terminal 1 were disrupted for about two hours Friday morning until a bomb squad determined that a piece of luggage abandoned on the curb was harmless.

The suitcase, which contained an electric heating pad, had been left outside Alaska Airlines, authorities said. Someone pointed out the bag to a skycap, who in turn notified a San Diego Harbor Police officer about 7:30 a.m. The officer’s dog, trained to sniff out explosives, reacted to the bag by sitting on it, Harbor police Lt. Jim Andrecht said.

The Metro Arson Strike Team was called in about 8 a.m. Harbor police detoured motorists away from the passenger drop-off curb in front of Alaska and United airlines, but allowed drop-offs in front of Southwest Airlines, Andrecht said.

Ticket counters at Alaska and United airlines also were closed. People who were in the terminal in those areas were moved to the baggage claim area so that they were further away from the suspicious suitcase, airport spokeswoman Diana Lucero said.

Southwest Airlines continued to process passengers, Lucero said.

Meanwhile, the bomb squad X-rayed the bag and saw nothing suspicious, so they opened it, San Diego Fire-Rescue Department spokesman Lee Swanson said. He said there was a heating pad with an electric cord in the suitcase.

Swanson said the bomb squad completed its investigation by about 9:30 a.m. The curbside traffic lane reopened, and Alaska and United airlines resumed passenger processing soon after.